It’s a sharp turnaround from November that may have reflected the unusually late Thanksgiving holiday.

Dallas-based Southwest said Wednesday that passenger revenue for every seat flown one mile last month rose between 14 percent and 15 percent from the same month in 2012. In November, the same figure declined 6 percent, and company officials blamed the drop partly on Thanksgiving falling on Nov. 28, meaning that some passengers returned home the following Sunday, Dec. 1.

The results include Southwest’s AirTran Airways subsidiary.

The per-mile revenue figure rises when average ticket prices increase and when more seats are filled.